Summary – An ATO audit is a detailed review of a business’s tax affairs to check whether reported income, expenses, deductions, GST and other tax information are accurate and supported by records. For a small business, the ATO may review tax returns, BAS statements, invoices, bank transactions, accounting records, payroll information and other supporting documents. Being selected for an audit does not automatically mean your business has done something wrong.
Receiving an Australian Taxation Office (ATO) audit notice can be stressful. For a small-business owner, the immediate questions are usually: Why me? What will the ATO ask for? How long will it take? Could I receive a penalty?
Understanding the process helps you respond calmly and properly.
What Is an ATO Audit?
An ATO audit is an examination of a taxpayer’s affairs to determine whether their reported tax position is correct and whether relevant tax obligations have been met.
Depending on the circumstances, an audit may examine:
- Business income
- Tax deductions
- GST and BAS records
- Business expenses
- Bank transactions
- Payroll and PAYG withholding
- Superannuation
- Asset purchases
- Motor vehicle expenses
- Private and business expenses
- Accounting records
- Invoices and receipts
The scope depends on the issue being examined. An audit may focus on one particular transaction or cover several areas of the business.
Is an ATO Review the Same as an Audit?
Not necessarily.
An ATO review may examine specific tax issues and give a business an opportunity to provide information or explain its position. If further examination is required, the matter may progress to an audit.
Therefore, receiving ATO correspondence does not automatically mean you are facing a full audit.
Why Would the ATO Audit a Small Business?
The ATO uses risk-based approaches and information available to it to identify tax matters that may require attention.
A business may receive questions when:
- Reported figures appear inconsistent
- GST reporting does not reconcile
- Deductions require further explanation
- Reported income differs from information available to the ATO
- Business and private expenses are difficult to distinguish
- Record-keeping concerns exist
- Information from different sources does not match
These circumstances do not automatically mean a business will be audited.
The ATO generally wants to establish whether the tax position reported by the business is accurate and supported by evidence.
What Happens During an ATO Audit?
Although every audit is different, the process generally follows several stages.
1. The ATO Identifies an Issue
The ATO identifies a tax matter requiring examination.
For example, an Australian electrical contractor may claim significant vehicle expenses. The ATO could ask how the expenses were calculated, what percentage represents business use and what records support the claim.
The objective is to determine whether the reported figures can be supported.
2. The ATO Requests Information
The ATO may send correspondence identifying the relevant financial year, transactions, documents required and response deadline.
Read the request carefully and prepare a checklist before responding.
3. You Gather Your Records
Depending on the audit, the ATO may request:
- Tax returns
- Profit and loss statements
- Bank statements
- Sales invoices
- Supplier invoices
- Receipts
- BAS Lodgement
- GST reconciliations
- Payroll records
- PAYG withholding records
- Superannuation records
- Asset registers
- Vehicle records
- Contracts and agreements
Good record keeping makes it much easier to explain how your tax figures were calculated.
4. The ATO Reviews Your Information
The ATO may compare:
Tax return → accounting records → invoices → bank transactions → BAS/GST records
For example, if a business claims $60,000 in advertising expenses, the ATO may ask who the suppliers were, what services were purchased, whether invoices exist and whether the expenses were genuinely business-related.
5. The ATO May Ask Follow-Up Questions
An audit can involve several rounds of questions.
For example, the ATO may ask about an $18,500 payment to a supplier. The business may explain that it was for website development. The ATO could then request the invoice, contract, bank transaction or other evidence.
This is why responses should be clear, factual and directly related to the question asked.
What Questions Might the ATO Ask?
Common questions include:
How did you calculate this deduction?
The ATO may request the calculation and supporting evidence.
Can you provide the invoice?
An invoice can establish what was purchased and from whom.
Was this expense entirely business-related?
This is particularly relevant to vehicles, travel, phones and home-office expenses.
How did you calculate the business-use percentage?
A business-use claim should have a reasonable basis supported by appropriate records.
Why does this amount differ from your BAS?
The ATO may request a reconciliation between accounting records and GST reporting.
Can you explain this bank transaction?
Unusual or unidentified transactions may require additional explanation.
What If You Cannot Find a Receipt?
Missing documentation can create problems during an audit.
Do not create or alter evidence to replace a missing document.
Instead:
- Check your accounting software.
- Review bank and credit-card statements.
- Contact the supplier for a replacement invoice.
- Look for other legitimate supporting records.
- Explain the situation honestly if the ATO asks.
A bank statement may show that money was paid, but it may not establish what was purchased or why it was a business expense.
What Happens If the ATO Finds an Error?
An error does not automatically mean a business will receive a penalty.
For example, suppose a business accidentally claims a $4,000 expense twice. The business may need to correct the error and pay any resulting additional tax and applicable interest.
This is different from deliberately concealing income or knowingly providing incorrect information.
Depending on the circumstances, an adjustment may involve:
- Additional tax
- General Interest Charge
- Administrative penalties
- An amended assessment
- Further compliance action
The outcome depends on the facts of the case.
Real-World Example: GST Reconciliation
Imagine a Melbourne hospitality business whose accounting system shows $550,000 in annual sales, while its BAS reporting does not reconcile.
The ATO asks the business to explain the difference.
The accountant investigates and discovers several transactions were incorrectly coded.
The business can identify the transactions, explain the error, reconcile the records, correct the relevant reporting and provide supporting evidence.
The practical lesson: regular GST and account reconciliations can identify problems before they become difficult to explain.
Does an ATO Audit Mean You Have Done Something Wrong?
No.
Being contacted by the ATO does not automatically establish wrongdoing.
The purpose of an audit or review is to examine relevant tax affairs and determine whether the reported position is correct.
The best response is:
Don’t panic, but don’t ignore the correspondence.
What Should You Do If Your Business Is Audited?
1. Read the ATO Notice Carefully
Identify the issue, financial year, documents requested and deadline.
2. Contact Your Accountant or Tax Agent
Provide the complete correspondence and relevant records.
3. Create an Audit Folder
Keep ATO correspondence, tax returns, BAS statements, accounting reports, invoices, bank statements and submitted responses together.
4. Reconcile Your Records
Check whether your:
Tax return ↔ accounting system ↔ bank records ↔ BAS ↔ supporting documents
are consistent.
5. Answer the Specific Questions
Provide relevant evidence rather than large amounts of unrelated information.
6. Keep Copies
Maintain copies of everything submitted and important communications.
How Can a Small Business Prepare for an ATO Audit?
Preparation should happen before the ATO contacts you.
Separate business and private transactions: A dedicated business bank account makes reconciliation easier.
Reconcile regularly: Monthly reconciliation can identify missing invoices, duplicate transactions, incorrect GST coding and unexplained payments.
Keep supporting documents: Store invoices, receipts, contracts and calculations in an organised system.
Document mixed-use expenses: Keep evidence supporting business-use percentages for vehicles, phones, travel and home-office costs.
Review BAS before lodgement: Check GST transactions and reconciliations rather than treating BAS preparation as a routine task.
ATO Audit Checklist for Small Businesses
Before responding to an ATO audit or review, check that you have:
- ☐ ATO notice and response deadline
- ☐ Relevant tax returns
- ☐ BAS statements
- ☐ Profit and loss reports
- ☐ Bank statements
- ☐ Sales invoices
- ☐ Supplier invoices
- ☐ Receipts
- ☐ GST reconciliations
- ☐ Payroll and PAYG records
- ☐ Superannuation records
- ☐ Asset records
- ☐ Vehicle records
- ☐ Supporting calculations
- ☐ Relevant contracts and correspondence
What Happens When an ATO Audit Is Finished?
There are several possible outcomes.
No Adjustment
The ATO may determine that the information provided adequately addresses its concerns.
Tax Adjustment
The ATO may determine that reported figures need to change, potentially resulting in additional tax, interest or penalties depending on the circumstances.
Further Compliance Action
Additional action may occur if significant issues remain unresolved.
If you disagree with an ATO decision, carefully review the correspondence. Depending on the type of decision, review, independent review or objection pathways may be available.
Need Help Preparing for an ATO Audit?
An ATO audit becomes easier when your business can answer one important question:
“Can we prove where this number came from?”
Accurate bookkeeping, regular reconciliations and organised supporting documents can make an ATO enquiry far easier to manage.
If your business has received an ATO audit or review notice, don’t wait until the deadline is approaching. Have the notice, relevant tax returns, BAS records and supporting documents reviewed early.
Contact an experienced Australian accounting and tax adviser today to review your situation, identify documentation gaps and help you prepare a clear, evidence-based response to the ATO.
Frequently Asked Questions
What happens when the ATO audits a small business?
The ATO identifies the issue, requests information, reviews records, asks follow-up questions where necessary and determines whether an adjustment is required.
What documents does the ATO need?
Depending on the audit, documents may include tax returns, BAS statements, invoices, receipts, bank records, accounting reports, payroll records and supporting calculations.
How long does an ATO audit take?
There is no universal timeframe. Complexity, record quality, the number of years involved and response times can affect the duration.
Can the ATO audit previous financial years?
Yes, depending on the circumstances and applicable rules. Businesses should retain historical records for the required period.
Does an ATO audit mean I have done something wrong?
No. Selection for an ATO review or audit does not automatically establish wrongdoing.
What happens if the ATO finds an error?
The business may need to correct the error and could face additional tax, interest or penalties depending on the circumstances.
